Kathy Fry, age 9, of Houston, Texas, for her question:
What is an air plant?
Every plant needs air, even more than we do. It needs to take in oxygen, just as we do. It also needs a supply of the waste carbon dioxide that we breathe out. But some places, even outdoors, tend to be stuffy. The special air plants are the ones that use a clever trick to get the air they need, even in a crowded jungle.
The experts who study plants are biologists. Their special branch of biology is botany. And, like all scientists, they have a lot of scientific words and terms to describe their favorite subjects. Botanists use the word "epiphyte." When you trace this word down to its roots, it means air plant. We all know that every plant needs plenty of air and ordinary folk might think that the notion of an air plant is downright ridiculous. But botanists know that they exist. When we call them epiphytes we show that we also know that air plants exist. The word sounds like It eppy fights."
Most plants have their roots in the soil and soak up moisture full of dissolved chemi¬cal foods. They also have their stems and leaves in the air to take in their needed supply of oxygen. Their greenery also needs sunlight to create sugary plant food from air and water. These everyday plants soon perish without enough soil and moisture, air and sun¬light. But a few members of the plant world refuse to give up, even when things get tough.
And things get tough when spreading shade trees crowd out the sunlight and take more than their share of oxygen from the air. A few plants have managed to overeome:th3s..impos¬sable plight. They just borrow the tall trees and perch high on their branches. There they can get the first helping of air and sunlight before it sifts down to the forest floor. You already have guessed that these airy plants are the epiphytes. And so they are.
The epiphytes must be rather small plants to perch high up there in the boughs. They must also be able to get along without roots which hold the plant firm and reach into the soil to obtain moisture and nourishment. Instead of roots, the epiphytes have special hold¬fasts to hook themselves on their sunny perches. They have plenty of sturdy green leaves to make their sugary food and they are adapted to soak moisture from the damp air, the dew and the rain. An epiphyte can make its own living and it never steals the sap food flowing through its friend, the tree.
The Spanish moss of the Southland is an epiphyte. Its holdfast hooks are gripped to the high boughs of a spreading tree. Its feathery, green gray foliage hangs down through the fresh, sunny air. Many other epiphytes are gorgeous orchids that perch high on the shoulders of the thick shade trees in the tropical jungles.
One of the most fascinating epiphytes lives in steamy jungles of the Old World. It is a twining vine of the dischidia family and its leaves are shaped like little pitchers. They trap moisture and blowing dust and the leafy pitchers become little flower pots filled with home made soil. Soon they sprout tiny roots and take nourishment from their pockets of soil. This dischidia is as well off as a plant rooted in the ground. Like all epiphytes, it only needs to borrow a perch on the shoulder of a tall tree.